Hi guys, I have a Lenovo ThinkCentre m57 and I really want to upgrade it. I've already asked a question and the answers were great, but they were not exactly straight-forward. Here is a picture of the size of my computer, said in millimeters:
It is pretty small and I know I will have a hard time finding a decent graphics card. I'm not looking for an amazing one that could run current games, but I am looking for one with at least 1 GB vram, 3.0 pixel AND vertex shader. I need these specifically because I want to be able to run Mirror's Edge and CoD4. All of my other specs are good enough to run them. Note that I currently have about 160 dollars but choose to not spend more than 50 dollars on my graphics card. I have found three on amazon and newegg that are fairly cheap and could potentially work on this computer; here are the links.
http://www.amazon.com/MSI-Profile-PCI-Express-R6450-MD1GD3-LP/dp/B004X6ABTM/ref=sr_1_22?s=pc&ie=UTF8&qid=1431307563&sr=1-22&keywords=graphics+card
http://www.newegg.ca/Product/Product.aspx?Item=N82E16814102933
http://www.newegg.ca/Product/Product.aspx?Item=N82E16814127584
Please tell me if they would be able to be used on this computer. If not please help me find one that could be compatible and not more than 50-60 dollars.

It is pretty small and I know I will have a hard time finding a decent graphics card. I'm not looking for an amazing one that could run current games, but I am looking for one with at least 1 GB vram, 3.0 pixel AND vertex shader. I need these specifically because I want to be able to run Mirror's Edge and CoD4. All of my other specs are good enough to run them. Note that I currently have about 160 dollars but choose to not spend more than 50 dollars on my graphics card. I have found three on amazon and newegg that are fairly cheap and could potentially work on this computer; here are the links.
http://www.amazon.com/MSI-Profile-PCI-Express-R6450-MD1GD3-LP/dp/B004X6ABTM/ref=sr_1_22?s=pc&ie=UTF8&qid=1431307563&sr=1-22&keywords=graphics+card
http://www.newegg.ca/Product/Product.aspx?Item=N82E16814102933
http://www.newegg.ca/Product/Product.aspx?Item=N82E16814127584
Please tell me if they would be able to be used on this computer. If not please help me find one that could be compatible and not more than 50-60 dollars.